Roll with adjustable deflection means



Aug- 2 1964 M. KANKAANPAA 3,146,150

- ROLL WITH ADJUSTABLE DEFLECTION MEANS Filed Aug. 1, 1960 sSheets-Sheet 2 INVENTOR I Mafffwhkaanpaa ATTOR EYS Aug. 25, 1964KANKAANPAA 3,146,160

ROLL WITH ADJUSTABLE DEFLECTION MEANS Filed Aug. 1, 1960 3 Sheets-Sheet3 INVENTOR Mai/f Kankampaa United States Patent 3,146,160 ROLL WITHADHJSTABLE DEFLECTION MEANS Matti Kankaanpaa, Beloit, Wis assignor toBeloit Iron Works, Beloit, Wis., a corporation of Wisconsin Fiied Aug.1, 1960, Ser. No. 46,450 2 ClmErns. (Cl. 162-305) The present inventionrelates broadly to the paper making and related arts, and is moreparticularly concerned with a roll structure and deflection means foruse therewith featuring a substantially fluid-tight chamber located inpartially encircling relation with respect to the roll structure forapplying a controllable pressure to the roll to accurately counteractthe forces tending to deflect the same.

It is known that at different stages during the course of papermanufacture roll structures of various types are employed forperformance of diverse functions. Illustrative of such rolls are wiredrive rolls, plain and suction press rolls, smoothing press rolls,pressure rolls, breakerstacked rolls, size press rolls, pull rolls,calender rolls and the like. Each of the mentioned types of rolls has incommon, for the purpose of the instant description, the use therewith ofmeans normally contacting the roll and tending to deflect the centroidalaxis thereof.

To illustrate, drive rolls mounted to engage the loop of the formingwire in a Fourdrinier type paper making machine engage the surface ofthe wire, and the weight or" the roll coupled with an applied loadarising from the resistance of the wire to being driven produce a forcecomponent which tends to deflect the drive roll in a directiondownwardly and toward the oncoming forming wire. As Well, in press rollcouples and in other roll arrangements wherein at least a pair of rollsare in nip-defining relation ship, the algebraic summation of theweight, the nip forces, the bending moments produced by the journalloading, and torque (if any) tends to produce in each of such rolls acurvature of its centroidal axis, in accordance with well known laws offlexure of materials. It is common to attempt to counter this effect bycrowning, i.e., by grinding the roll slightly barrel shape in an amountand curvature calculated to offset the curvature under operatingconditions.

The normal deflection, when concave toward the wire wrap, on a wiredrive roll, if not relieved, tends to cause the off-running portion ofthe forming wire to be compacted or squeezed laterally, which increasessubstantially the wear on the wire. The initial investment in a formingwire is very substantial, but even more important, the pro duction lossduring wire replacement is frequently enormous.

Specifically as to press rolls, a different problem exists. Productionschedules for many paper machines require relatively frequent changes inthe type and grade of product. Certain grades of paper demand that thepressing and other treatment not reduced significantly the thickness orcaliper of the web, and this in turn requires that the nip loads in apress couple be relatively light. On the other hand, certain other paperproducts required from the same paper machine permit or even demand moresevere pressing, and in order to achieve some measure of versatilitywith the same paper machine, one practice followed by the art toaccomplish the noted changes is the removal of the press rolls forregrinding to a different amount of crowning. Obviously, this practiceis also both expensive and time consuming. And as will be later noted,crowning of the roll causes diiferences in the surface speed of the rollbetween the central and end portions of the roll, which is often harmfulto the function of the press.

It is accordingly an important aim of the instant inven tion to providea roll assembly embodying therein novel means to counteract the forcestending to deflect the roll.

3,146,160 Patented Aug. 25, 1964 Another object of this invention liesin the provision of an improved paper machine arrangement comprising aroll, means normally contacting the roll and tending to deflect thecentroidal axis thereof, and means forming with the roll a substantiallyfluid-tight chamber for applying a controllable pressure to said roll tocounteract the forces tending to deflect the roll.

A further object of the present invention is to provide improvedapparatus for relieving deflection in a roll member, comprising meansforming a substantially fluid-tight chamber located in partiallyencircling relation with respect to the roll member, and means forsupplying a pressurized fluid to the chamber at a pressure calculated tocompensate for the weight of the roll member and other forces causingsaid deflection.

Other objects and advantages of the invention will become more apparentduring the course of the following description, particularly when takenin connection with the accompanying drawings.

In the drawings, wherein like numerals designate like parts throughoutthe same:

FIGURE 1 is a diagrammatic view showing forces applied to a drive rollin a Fourdrinier type paper making machine;

FIGURE 2 is an exaggerated essentially diagrammatic top plan view of adrive roll mounting of the prior art;

FIGURE 3 is an essentially diagrammatic side elevational view of thedevice of FIGURE 2;

FIGURE 4 is a diagrammatic top plan View drawn along the lines of FIGURE2, but showing an embodiment of the instant invention;

FIGURE 5 is a diagrammatic Side elevational view, with parts taken insection, of the device of FIGURE 4;

FIGURE 6 is a view similar to FIGURE 5, but showing the deflectionrelieving means of this invention as applied to a press couple;

FIGURE 7 is a diagrammatic end elevational view, with parts in section,of the arrangement of FIGURE 6;

FIGURE 8 is a view similar to FIGURE 6, and illustrative of the use ofthis invention in association with both rolls of a press couple;

FIGURE 9 is an essentially diagrammatic side elevational view, withparts therein taken in section, of a further roll assembly embodying thenovel concepts of this invention;

FIGURE 10 is a view like FIGURE 8, but illustrative of a calender stackwith the king roll partially encircled by the pressure applying means ofthis invention;

FIGURE 11 is a vertical sectional view through a roll structurefeaturing pressure applying means located interiorly of the roll;

FIGURES 12 and 13 are detail sectional views to more fully illustrateexemplary forms of side seal arrangements which may be employed; and

FIGURE 14 is a detail sectional view of one form of end sealarrangement.

The description now to follow will be first directed to FIGURES l to 5,the latter two views being illustrative of a wire drive roll and themeans of this invention forming a substantially fluid-tight chamber forapplying a controllable uniformly distributed pressure to the wire driveroll to counteract the forces tending to deflect the roll. However, itwill be apparent when reference is made to FIGURES 6 to 11 that theinvention is not restricted to a wire drive roll. In fact, the inventionis of important application to any roll structure, whether or not usedon or off a paper machine, and it is within the contemplation of thisinvention that the deflection relieving means herein disclosed willproduce substantial improvements on rolls used in steel mills and otherindustries.

As well, the invention is of important application in combination withconventional loading applied at the journals of a mating roll and/orwith a straight roll or a roll having conventional crown. By regulatingthe forces produced by the fluid chamber of this invention, incooperation with journal loading, there is thus obtained a novel mannerof altering the shape of the nip pressure profile.

It has earlier been the accepted practice in a Fourdrinier type papermaking machine to drive the forming wire through the suction couch roll,however, recently it has been found advantageous to use the return rollsas drive rolls and to drive the wire with drive rolls mounted outsidethe loop of the wire and engaging the outer surface of the wire. In thecase of such rolls the wire passes over the top of the drive rolls.

While these changes in the wire drive arrangement have resulted in amuch longer wire life, it is apparent that many further improvements canbe made. Specifically, it is known that the drive roll has a tendency todeflect from its own weight and forces applied thereto, and suchdeflection curvature causes at least a compacting together of the wovenelements of the wire, and in some cases an overlapping or ridging ofsmall portions of the wire. These conditions markedly increase wear onthe wire and may destroy its usefulness.

This may be more fully understood when reference is made to FIGURE 1,which is a diagram showing some of the forces applied to a drive roll20. The wire 12 (traveling in the direction indicated by the arrow)passes over the top of the roll 20 and wraps the roll 20 by a totalangle of wrap of 2 alpha. As here shown the oncoming side 12b of thewire 12 wraps the roll 20 over the angle alpha and the off-running side120 of the wire also wraps the roll over the angle alpha with thedividing line v therebetween being a substantially vertical line passingthrough the center of the roll 20. The tension on the wire 12 thusapplies a force in an essentially downward vertical direction indicatedby the arrow A.

The weight of the roll 20 also applies a force in the direction of thearrow A. It will be appreciated that loading forces such as the weightof the roll and the tension on the wire 12 load the roll 20 as a beam.And the roll 20 has a substantial length compared to its diameter. Forexample, in a typical paper machine the roll 20 will be approximately 20feet long and approximately 1 feet in diameter.

It will further be appreciated that, when the roll 29 is rotated in thedirection indicated by the arrow (on the roll 20) there is a loadapplied across the top of the roll in a direction generally tangentialto the roll portion wrapped by the wire 12. The wire 12 resists beingdriven to this extent so as to apply this load to the roll 20 and thisload applies generally in the direction of the line of force B. Theresulting sum of all of the loads applied to the roll 20 may beindicated by the force line C and this generally is the direction inwhich the roll 20 tends to deflect the centroidal axis thereof. It willbe noted that the roll tends to deflect in a direction downwardly andtoward the oncoming wire (12b).

Referring now to FIGURES 2 and 3, it will be seen that the deflection isshown in exaggerated form. In FIGURE 2 the roll 20 is shown rotatablydriven by drive means 23 (indicated diagrammatically) and both journals23 and 24 rotatably mounted in bearing means 25. The wire 12 passes overthe top of the roll 26; and it will be seen that the roll 20 isdeflected in its central portion 20a backwardly or in the direction ofthe oncoming side 12b of the wire 12. Or as may be otherwise stated, theindicated centroidal axis 20c is deflected. As shown in FIGURE 3, thecentral portion 29a of the roll 20 is deflected elf-center from thedrive means 23 and the extreme edge of the roll, which is a full linemarked 20. The central portion 20:: is deflected toward the oncomingside 12b of the wire and also downwardly. The curvature of the rollsurface, although not visible,

reorients the driving eifort forces so that their lines of action tendto converge, resulting in the application to the wire of transverseforces in the directions indicated by the arrows E of FIGURE 2. Thus,although the oncoming side 12b of the wire 12 may have no transverseforces applied thereto and the wire 12 may be traveling in substantiallya straight line" in a plane generally tangential to the roll 20 (asindicated by the arrows b), as the wire 12 passes over the bowed ordefiected roll 20, there is a tendency to narrow the wire at theoff-running side 120 (as indicated by the arrows c). This transversecompression of the otf-running wire side 12c tends to offer anopportunity for the wire to ridge, particularly if any slight forces maybe applied normal to the plane of the wire (for example, by fibers orsome dirt or impurity adhering to the roll 20 and passing between theroll 20 and the wire 12).

In FIGURES 4 and 5, there is shown one embodiment of the instantinvention for relieving deflection in a roll member. A drive roll 30 isdriven by suitable drive means 31 (shown diagrammatically). Bearingmeans 33 rotatably mount the journals 32 and 34 of the roll 30. A wire35 passes over the roll 30 and is driven thereby in the directionindicated by the arrows in FIGURE 5.

To compensate for the curvature normally produced by the forces abovedescribed, there is provided adjustable deflection means generallydesignated by the numeral 36. In the form shown in FIGURE 5, thedeflection means 36 comprises a generally semi-cylindrical tank portion37 preferably extending extending substantially entirely along thelength of the roll 30 and reinforced by a plurality of axially spacedstrengthening ribs 38, only one of which is shown in FIGURE 5. The tankor gland 36 defines therewithin a substantially fluicl tight chamber 39for containing a suitable pneumatic or hydraulic fluid, which may beair, gas, water, oil, liquid metal or other fluids, depending upon theintended application. The chamber 39 is sealed against substantial fluidleakage at the sides and ends of the roll 30, and side seal means 40 areshown in FIGURE 5, although specific reference will be later made to thedetails of exemplary forms of end and seal means. Although shownencompassing approximately one half of the roll periphery, chamber 39may span a lesser part of the periphery.

Fluid is admitted under pressure to the deflection relieving chamber 39by a connection 41 within which is located pump means 42 (showndiagrammatically). The fluid selected should be of the minimum viscosityconsistent with low leakage losses at the pressures required to minimizethe power required for rotation of the roll. Generally, air is found tobe most advantageous.

The tank or gland 37 is supported along its length in any suitablemanner, for example, by a plurality of beam members 43. The arcuatecenter or point p on the tank or gland 37 is ordinarily mounted on linewith the sum of all the forces applied to the roll 30, this force linehaving been indicated as C in FIGURE 1. The precise radial direction ofthe force line may vary somewhat depending upon the wire tension loadand the load imposed by driving of the wire 35, and accordingly, it isdesirable that means be provided to circumferentially shift thedeflection means 36. As for example, the tank or gland 37 may mountbearing means 44 at opposite ends received coaxial with shaft 39a of theroll 30. To then shift the gland 36 circumferentially to align the pointp with the force line, one or more of the web members 38 may mountbracket means 45 to which is connected piston 46 of cylinder means 47,rigidly mounted as shown.

Thus by suitable regulation of the fluid pressure within and position ofthe gland 37, the deflection curvature of roll 39, normally resultingfrom the weight and the applied forces, may be exactly equalled orcancelled, or either an under or overcorrection may be applied asdesired. Since the gland 37 contains a uniformly distributed pressure,its effect upon the roll may precisely correspond to the substantiallyuniformly distributed forces, that is, the weight of the roll body, thewire tension, nip loading, and the like, without signficant forcecouples which would introduce changes of shape in the flexure curve ofthe roll. As arrows, d, indicate in FIGURE 4, the wire thereby leavesthe roll 39 in full width with the driving forces orientednon-convergently.

In addition to effectively counteract the normal roll deflection, thepressure applying means 36 of FIGURES 4 and 5, as well as the similarmeans in FIGURES 6 to 11, has further advantages. First, since theframework beam members 43 take part or all of the load, smaller rolls,lighter weight rolls and shells, and smaller, cheaper bearings may beused. Second, by the disclosed structure, no undesirable bending momentsoccur, but instead, there is provided an essentially true or straightroll. Third, and as is believed now apparent, the adjustable deflectionmeans of this invention is well adapted for use with existing rollstructures.

It was earlier noted that the adjustable deflection means of thisinvention is not restricted in use to paper machine drive rolls, butalso produces highly advantageous results in any roll assembly comprisedof two or more rolls between which a uniform nip pressure is requiredacross the contacting faces thereof. Illustrative of such rollassemblies are paper machine plain press rolls, smoothing press rolls,pressure rolls, breaker stack rolls, size press rolls, pull rolls,calender rolls and the like. A few of the divers applications for theinstant invention are shown in FIGURES 6 to 11, and with reference firstto FIG- URES 6 and 7, it will be observed that an adjustable deflectionmeans 360 may be employed in connection with a bottom press roll 50defining a nip N with a top press roll 51. The adjustable deflectionmeans 36a in FIG- URES 6 and 7 includes a gland portion 53 mounting sealmeans 54, and constructed of circumferential members 55 joined to beammembers 56 secured at opposite ends to rigid structure, as shown inFIGURE 7, whereby the reactions of force applied to the roll body 59 aretransferred to said structure. Of course, the tank or gland member 53may be circumferentially shiftable as in FIG- URE for the same purpose,although in FIGURES 6 and 7 a rigid structure is shown, and in eithercase the beam and web members must be sized and arranged to resist therequired fluid pressure within and the portions of the forcetransferred. The forces thus are transferred, not via the rolljournal-bearing structure as now practiced in the art, but via thestructures provided by beams and webs such as '56 and 55.

As appears in FIGURE 7, the lower press roll 5G is provided at oppositeends with journals 57 and 58 received in bearing means 59 and 61),respectively. Such bearing means may be fixedly mounted, or providedwith means for permitting, when required, separations between the rolls.In either case either or both rolls may be provided with driving means.When one of the rolls is driven, it is desirable to provide also for thedeflections due to torsional load produced by the driving effort.

The top press roll 51, likewise, mounts journals 61 and 62 rotatablyreceived in bearing means 63 and 64-, respectively, and preferably isfixed in location when roll 50 is movable or vice versa.

It was earlier pointed out that different grades of paper requiredifferent nip loads, and that the different grades may be produced onthe same paper machine. Furthermore, it is often desirable to alter niploading for other reasons. However, to accomplish this it has previouslybeen required to remove the press rolls for regrinding to a differentamount of crowning, crowning of course being practiced in an endeavor toobtain uniform nip loads across the contacting roll faces or to accept adegree of non-uniformity as expedient. To remove the press rolls and toeffect regrinding is obviously a time consuming and expensive procedure.These (lllI'lCllltlBS are herein eliminated by the adjustable deffectionmeans 36a which counteracts or relieves deflection of the press rolls 5tand 51 to provide uniform nip pressures entirely along the roll contactline.

Referring again to FIGURE 7, it is now apparent that this invention mayalso be advantageously employed to over-correct the curvature due to thenormal function by applying in the chamber 37 a pressure in excess ofthat required to balance the forces normally creating the deflection.The roll 5%) would then, for example, be curved concave upward, thebearings 59 and 60 then exerting a net force downward on the journals 57and 58 respectively. By then applying downward forces to the bearinghousings 63 and 64, a graduated nip load distribution may be obtainedhaving a maximum value substantially at the mid span of the nip anddecreasing to a lesser value at the end points of the nip. It islikewise evident that by combining the conventional methods of applyingloads to roll couples at their journals with the pressure gland 3 6 thatsome crown curvature may be advantageously combined. It this case by thesimple manipulation of the pressure contained within the chamber 36,either an untier-compensation or an over-compensation may be providedwhich permits the adjustment of the nip pressure distribution profile toprovide a higher value at the ends with respect to the mid span or thelower pressure value at the ends as previously described.

It is noted that the adjustable deflection means 366! of FIGURES 6 and7, while shown as stationary, could as well incorporate means forshiftng the tank portion or gland 53 so as to locate its center inalignment with the loads to be relieved. As well, in all forms of theinvention various pneumatic or hydraulic fluids can be employed, air orother gaseous materials being indicated in FIGURES 4 and 5, while inFIGURES 6 and 7 the pressure applying means is Water, although otherhydraulic media could as well be used.

In FIGURE 8 adjustable deflection means 36!) and 36c are employed inpartially encircling relation with respect to an upper press roll 60 andlower press roll 61, respectively. The structure of the deflection means36b and 360 in FIGURE 8 is essentially identical to that shown inFIGURES 6 and 7, and accordingly like numerals have been appliedthereto, with the suflix a attached.

As in FIGURES 6 and 7, the rolls 60 and 61 are plain press rolls.However, it is within the contemplation of this invention that thedeflection means herein disclosed may be used in connection with aback-up roll, the latter roll being in contact with a suction press rollwhich in turn is in nip defining relation with a plain press roll.

The pressure applying fluid in FIGURES 7 and 8 may be any of the mediaearlier indicated, and as well, the deflection means 36b and 360 may beconstructed to permit circumferential shifting, in the event it wasdesired to position the rolls 60 and 61 in non-vertical alignment.

In any event, in order to obtain uniform nip loads across the contactingfaces of the rolls 60' and 61, the pressure applied by the lowerfluid-tight chamber 36a is determined by the nip load at Nl plus theweight of the bottom roll 61, while the pressure applied by the upperfluid-tight chamber 36a is determined by the nip load less the weight ofthe top roll 60. By so proceeding, the nip loading can be varied foreffective pressing of various grades of paper, and yet uniform nippressures obtained across the roll faces by controlling the relativepressures in the upper and lower fluid-tight chambers 36a in the mannerindicated.

Certain press applications employ a roll couple wherein the roll partsthereof are generally horizontally aligned or in this approximaterelationship. The instant invention also accomplishes highlyadvantageous results therewith, and an exemplary arrangement of thistype structure is shown in FIGURE 9. A press couple generally designatedat 65 and comprising press rolls 66 and 67 is shown as incorporatingtherewith adjustable deflection means 36a. The force counteracting means36d is desirably constructed in the manner of the structure 36a, andaccordingly, as in FIGURE 8, like numerals with the suflix a have beenappended to like parts.

The deflection means 36d in FIGURE 9 is indicated with its arcuatecenter 2 generally in horizontal alignment with the radial centers ofthe rolls 66 and 67. The relative position of the deflection means withrespect to the roll 66 of course depends upon the weights of both rolls66 and 67 and the nip load at N2. As for example, if in a particularapplication the nip load was pounds per lineal inch of each roll and therolls weighed the same amount, it is readily apparent by summing thevectors the deflection means 360. would then be shifted approximatelycounterclockwise. However, regardless of the relative position of thedeflection means 36d with respect to the roll 66, the pressure appliedby the gland 53a is equal to the nip loading, although of course, whenthe rolls 66 and 67 are generally horizontally aligned as shown, theroll weights would not exert any substantial forces needing to berelieved.

It is of course apparent that both of the rolls 66 and 67 could bepartially encircled by an adjustable deflection means, and normally theroll 67 would be the drive roll, although this would depend somewhatupon the particular sheet being pressed.

Under certain circumstances the combination described or variationsthereof are advantageously applied in a calender such as shown in FIGURE10. This provides a great increase in the versatility of either a presscouple or a calender stack, permitting the papermaker to quickly andconveniently compensate for inevitable variations in the paper web,which compensation has never previously been available to him.

Referring now to FIGURE 10, there is shown 21 calender stack generallydesignated by the numeral 70 and comprising a bottom or king roll 71 anda plurality of relatively smaller diameter rolls 7275 in generalvertical alignment therewith. As is the practice in the art, thecalender stack 70 is supported by a suitable frame (not shown), and theking roll is mounted in fixed bearings while the rolls 72-75 thereaboveare so mounted to permit a degree of vertical movement. Since thebearing structure is conventional and forms no part of the instantinvention, specific showings thereof have been omitted.

It is also known that the king roll 71 carries the weight of the rolls72-75 and the bearings therefor, and accordingly, it has been the priorart practice to crown the king roll 71 to compensate for its deflectionand to thereby attain generally uniform nip pressures. However, crowningis a relatively expensive machining operation and eventually recrowningis necessary because of gradual wear on the king roll. In addition, aswas noted, the different peripheral speeds along various portions of theroll is often disadvantageous in press applications, and of course, aparticular crown is only satisfactory for a specific load condition.

These problems are herein avoided by provision of deflection means 36::constructed as shown in the same manner as the earlier described formsof the invention, and accordingly bearing like numerals with the suffixa appended thereto. To compensate for deflection in the bottom or kingroll 71, pressure is applied by the chamber 53a in an amount essentiallyequal to the nip load at N-3 and the weight of the king roll 71.

It may be observed from the preceding description directed to FIGURES 4to 10 that the force relieving pres- Sure is applied against the outerdiameter of one or more rolls. The forces tending to deflect a roll canalso be counteracted by the relieving pressure being directed againstthe inside surface or diameter of a roll, and this is shown in FIGURE11. As appears therein, a roll generally designated by the numeral 89may comprise an outer annular shell 81 and a coaxially spaced innerannular shell 82, the shells 81 and 82 receiving therebetween seal-means83 and 84 to define a pair of substantially fluid-tight chambers 85 and86. The inner shell 82 is of course stationary while the outer shell 81rotates thereabout by connection with suitable drive means (not shown).This arrangement resembles the familiar suction roll, in that theinternal member is stationary and surrounded by a rotatable shell.

The roll may be employed in any one of the applications earlier listed,and in order to relieve the forces tending to deflect the roll 80 apositive pressure can be applied to the chamber 85, or alternatively, anegative pressure can be applied to the chamber 86. Thus, a pres surizedfluid can be admitted to the chamber and no fluid to the chamber 86, orno pressure applied in the chamber 85 and vacuum applied in the chamber86. In either event, there exists a pressure difference between thechambers 85 and 86, and this is controlled to essentially equal theforces tending to deflect the roll, which are of course, the roll weightplus nip loads or the forces applied by the forming wire when the roll80 is used in an application of the type illustrated in FIGURES 4 and 5.

It will of course be appreciated that the stationary roll member 82 maybe of solid construction, rather than in the shell form shown, and thatfluid can be admitted to either of the semi-circular chambers 85 or 86.The chambers are of course sealed at opposite ends of the rolls 81 andS2, and illustratively, oil may be pumped into one of the semi-circularchambers 85 or 86 between the nonrotating roll 82 and rotatable shell 81to provide a roll structure which is completely floating on oil.

This described arrangement permits a smaller diameter roll to beemployed, as contrasted with the conventional journal roller, andfurther, this smaller diameter roll produces a substantially higherspecific pressure since the line of contact is smaller.

Seal means 40 and 54 have been somewhat diagrammatically illustrated inthe preceding views as located in close running relation with the outerdiameter of the roll to seal the chamber 39 or 53 and to reduce leakageof the pressure relieving fluid in the chamber. The particularconstruction of the seal means may be widely varied, and in FIGURES 12and 13 two exemplary forms of side seals are illustrated. As appears inFIGURE 12, tank or gland T is provided with a pair of side wall portions90 and 91 connected at 92 and mounting plate means 93 to which isattached a rubbing strip 94 to wipe from roll R fluid in chamber 95.

Located thereabove and attached to the tank side wall portion 98 isbracket means 96 supporting a sealing strip 97 of a suitable plasticcomposition, shown as angularly disposed and in sealing relation withthe roll R at 98. As is illustrated, the strip 97 is passaged at 97a toequalize the pressures on opposite sides thereof. To urge the sealingstrip 97 into the position shown, inflatable tubular means 99 supportedby mounting means 100 may be employed. The fluid to inflate the tubularmember 99 is desirably air, and it is believed now apparent that duringrotation of the roll R partially submerged in pressure relieving fluidin the tank T, excess fluid is wiped from the roll by the flexible strip94 and substantial leakage of fluid passing the wiping strip 94 isprevented by the effective seal provided by the strip member 97.

The seal means may also take the form shown in FIG- URE 13, wherein likenumerals have been employed to designate like parts in FIGURE 12. Asappears therein, mounting means 191 supports a seal member 102 having aplurality of grooves 102a formed therein. A fluid such as water issupplied from a conduit 193 by a pump means 104 through a connection 105to the groove pattern to not only effectively seal the roll structureagainst excessive leakage, but to provide a lubricative effect. As inFIGURE 12, a wiping strip 106 may be employed, and this is convenientlymounted by the block member 191.

It is further desirable that the roll structure be sealed at oppositeends, and for this purpose the arrangement in FIGURE 14 may be employed.Tank or gland T located as earlier indicated with respect to roll R maymount at opposite ends web or rib members 107 to which is bolted orotherwise secured a semi-annular cap memher 108. The cap member issuitably grooved to receive a plurality of inflatable tubular members109 bearing against a semi-annular seal member 110 located in closerunning relation with opposite ends of the roll R. If desired, the sealmeans 110 may be secured to the cap member 108 at 111, and to achievethe desired lubricity between the seal means and the roll R, water orother fluid media may be directed between the roll ends and inner faceof the seal means 110. As in FIGURE 12, the inflatable members 109 maycarry air to force the seal means 110 into good sealing relation withthe roll R, to prevent excessive fluid leakage from the tank T.

It has been noted hereinabove that the pressure relieving fluid used inthe gland or tank chamber is susceptible of wide variation, and a numberof pneumatic and hydraulic fluids were mentioned. It is desired if aliquid is employed to utilize a relatively low viscosity fluid in orderto not introduce substantial fluid friction forces, which would have theeflect of increasing the power requirements to drive the roll structuresdisclosed. It has further been stated hereinabove that the pressurerelieving fluid is controlled in pressure to the desired level tocompensate properly for the forces tending to cause roll deflection, andthis can be attained either by control of the pump means 42, or by useof a conventional pressure regulator.

In this connection, the relieving pressure is actually relatively smallsince the area against which the relieving pressure acts is relativelylarge, and in the ultimate case, the area is the product of the rollouter diameter and roll face in contact With the pressure relievingfluid. As a specific example, assuming a maximum nip pressure in a presscouple application of 300 pounds per lineal inch, a roll Weight of 170pounds per lineal inch, a roll diameter of 44 inches, and a roll face of1 inch in contact with the pressure relieving fluid. Assuming that theroll to be relieved is in the bottom position and the outside loadsoperating thereon are essentially vertical, the pressure required in thepressure relieving chamber can readily be calculated to be 10.8 poundsper square inch. As is apparent, this value can be readily attained withmany fluids by conventional pressure control systems.

It is of course appreciated that some fluid leakage will occur, eventhough seal means are employed as described. If air is employed as thepressure relieving fluid, illustratively it can be assumed that thetotal leakage area would be equivalent to about a one-half inch diameterorifice. Assuming a gauge pressure within the pressure relieving chamberof 1S p.s.i.g., the leakage air flow is about 108 cubic feet of free airper minute. The theoretical horsepower required to compress this airvolume from atmospheric pressure to 15 p.s.i.g., using single stageadiabatic compression, is approximately 5.4 horsepower.

As is further appreciated, the pump means 42 are effective to direct tothe pressure relieving chamber defined by the tank or gland suflicientfluid to replace the small amount of fluid lost by leakage. In thisconnection, suitable trap means would be employed to collect the fluidleakage and any overflow into the nonpressured, or low pressure chamber,and in the roll structure of FIGURE 11 it may be desirable to provide adrain connection diagrammatically indicated at 112 and communicatingwith the chamber 86 to drain excess fluid therefrom through an end ofthe roll structure 82.

The numerous applications for the instant invention, in the papermachine art and in other industries wherein roll deflection problems arepresented, have been pointed out hereinabove, and as well the differentfluids which could be used for pressure relieving purposes have beenstated. Numerous structural embodiments of the invention have beenillustrated and described, and it is accordingly believed quite apparentthat numerous other changes and modifications can be effected withoutdeparting from the novel concepts of this invention.

I claim as my invention:

1. Apparatus for controlling the deflection in a roll member, comprisingmeans forming a substantially fluidtight chamber located in partiallyencircling relation with respect to the roll member, means for supplyinga pressurized fluid to said chamber at pressure calculated to oppose theforces tending to cause said deflection, and means for shifting thechamber circumferentially with respect to the roll member to locategenerally the center of said chamber in alignment with the sum of allforces tending to cause the deflection.

2. Apparatus for controlling the deflection in an imperforate rollmember, comprising a tank wrapping a portion of the circumference of theroll member and spaced radially therefrom to provide with said rollmember a force relieving chamber, seal means between said tank and rollmember to prevent excessive leakage of fluid, and means for supplying apressurized fluid to said chamber at a pressure calculated to balancethe forces tending to cause said deflection, and means for shifting thechamber circumferentially with respect to the roll member to locategenerally the center of said chamber in alignment with the sum of allforces tending to cause the deflection.

References Cited in the file of this patent UNITED STATES PATENTS705,071 Graham July 22, 1902 1,563,130 Weston Nov. 24, 1925 1,870,971Sundstrom Aug. 9, 1932 2,395,915 Specht Mar. 5, 1946 2,648,122Hornbostel Aug. 11, 1953 2,877,694 Thiessen Mar. 17, 1959 2,908,964Appenzeller Oct. 20, 1959 2,911,040 Hornbostel Nov. 3, 1959 3,031,872Kusters May 1, 1962 FOREIGN PATENTS 1,037,397 Germany Aug. 28, 1958

1. APPARATUS FOR CONTROLLING THE DEFLECTION IN A ROLL MEMBER, COMPRISINGMEANS FORMING A SUBSTANTIALLY FLUIDTIGHT CHAMBER LOCATED IN PARTIALLYENCIRCLING RELATION WITH RESPECT TO THE ROLL MEMBER, MEANS FOR SUPPLYINGA PRESSURIZED FLUID TO SAID CHAMBER AT PRESSURE CALCULATED TO OPPOSE THEFORCES TENDING TO CAUSE SAID DEFLECTION, AND MEANS FOR SHIFTING THECHAMBER CIRCUMFERENTIALLY WITH RESPECT TO THE ROLL MEMBER TO LOCATEGENERALLY THE CENTER OF SAID CHAMBER IN ALIGNMENT WITH THE SUM OF ALLFORCES TENDING TO CAUSE THE DEFLECTION.